Previously, Nokia had committed much of its smartphone efforts to the antiquated and ultimately doomed Symbian operating system.

The $250 million is part of a series of "platform support payments" Microsoft will pay Nokia to continue using and collaborating on Windows Phone.

These support payments in combination with "software royalty commitments" will amount to billions of dollars in the long run.

More fun facts from Nokia's earnings yesterday: the company did ship more than one million Windows Phones as we'd previously heard, but lost about $1.4 billion in profits in 2011, down 43% year over year.

Remember, though, that Nokia's first Windows Phone only hit shelves in November.